lincolnandstevendouglas.they were part of the race for one of illinois's two senate seats. lincoln lost the debates and elections, but the conversations launched him into national prominence and lincoln went on to become one of the the greatest presidents today. what if that's what got him killed, changing the course of the nation? the next guest tells the story of an assassination plot wider and far more sinister than we imagined. joining us is timothy o'brien, the executive editor of the huffington post and the author of "the lincoln conspiracy." >> it's great to be here, s.e. >> i love alternative history and the kinds of things eric larson does with history. this is a combination of history and fiction. tell me, was this a conspiracy you actually believe in? do you think think this is what happened or did you dream this up to sort of enhance a novelistic new version of history? >> lincoln conspiracy is a historical thriller about this incredible moment of change after the lincoln assassination and the industrialization of america and cities and society and ferment. and the assa